Phospholipid and cholesterol are the essential components of the lipid matrix in which are embedded the protein components of cellular membranes. The central objective of this proposed study is to investigate relationships in vascular muscle of the fluidity of this lipid matrix, the methylation of phospholipids, movements of calcium and the contractile response of vascular smooth muscle. An additional objective is to characterize the modulation of the fluidity of the lipid matrix by pharmacologic agents and dietary components. A specific objective of highest priority is to define the relationship between calcium blocking agents and phospholipid methylation in the mobilization of calcium in vascular smooth muscle. The study will explore in normal blood vessels the relations between fluidity and function that may be applicable to hypertension and the modulation of hypertension. This study will evaluate the hypothesis that methylation of phospholipid plays a crucial role in the mobilization of calcium for the contractile response of vascular muscle.